KSPROPERTY_CAMERACONTROL_ZOOM_RELATIVE
The KSPROPERTY_CAMERACONTROL_ZOOM_RELATIVE property specifies the zoom status of the camera.
Usage Summary Table
| Get | Set | Target | Property descriptor type | Property value type |
|---|---|---|---|---|
| Yes | Yes | Filter or node | KSPROPERTY_CAMERACONTROL_S or KSPROPERTY_CAMERACONTROL_NODE_S | LONG |
The property value (operation data) is a LONG that specifies a camera's relative zoom setting. The size of the value represents the desired zoom speed; a higher value represents a higher speed.
| Value | Description |
|---|---|
| 0 | Stop zoom lens motion. |
| Positive value | Start moving the zoom lens in the telephoto direction (initiate zoom-in). |
| Negative value | Start moving the zoom lens in the wide angle direction (initiate zoom-out). |
Remarks
The Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure specifies the relative zoom.
Note that a particular device might support only a certain speed range. To determine the range of speeds supported by the device, an application can issue a KSPROPERTY_TYPE_BASICSUPPORT request. You can specify KSPROPERTY_TYPE_BASICSUPPORT in the Flags member of the KSPROPERTY_ITEM structure.
Some devices support only a single zoom speed. In this case, the sign of the Value member indicates whether the lens should zoom in or zoom out.
When making a set request, the client should supply one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure.
When making a get request, the client receives one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure. The value indicates the current zoom status of the camera.
Requirements
Header: ksmedia.h (include Ksmedia.h)